Bio Exam II

Question 1

osmoregulation

Answer 1

regulation of solute concentrations and the balance of water

Question 2

osmosis

Answer 2

movement of water from a region of higher concentration to a region of lower concentration

Question 3

osmolarity

Answer 3

solute concentration of a solution that determines the movement of water across a semi permeable membrane

Question 4

iso-osmotic

Answer 4

movement of water is equal in both directions

Question 5

what happens is two solutions differ in osmolarity?

Answer 5

the net flow of water is from the hypo-osmotic to the hyper-osmotic

Question 6

hypo-osmotic

Answer 6

solution with lower concentration of solute

Question 7

hyper-osmotic

Answer 7

solution with a higher concentration of solute

Question 8

the fluid with the highest osmolarity is?

Answer 8

seawater in a tidal pool

Question 9

osmoregulation and excretion are?

Answer 9

mechanisms that maintain volume and composition of body fluids

Question 10

organisms categorized as osmoconformers are most likely?

Answer 10

marine species

Question 11

osmoconformers

Answer 11

consists only of some marine animals, are iso-osmotic with their surroundings and do not regulate their osmolarity

Question 12

osmoregulators

Answer 12

expend energy to control water uptake and loss in a hyper-osmotic

Question 13

osmoregulator examples

Answer 13

most vertebrates -
all freshwater fishes
most amphibians
all terrestrial animals

Question 14

osmoconsumers

Answer 14

all marine invertebrates
elasmobranches (sharks, rays, and hagfish)

Question 15

osmolarity of osmoregulators is

Answer 15

1/3 rd of seawater

Question 16

Freshwater animals

Answer 16

constantly take in water by osmosis from their hypo-osmotic environment
they lose salts by diffusion and maintain water balance by excreting large amounts of dilute urine
salts lost by diffusion are replaced in foods and by uptake across the gills

Question 17

Marine animals

Answer 17

constantly lose water by osmosis from their hyper-osmotic environments
gain salts by diffusion and maintain water balance by not peeing

Question 18

energy of osmoregulation

Answer 18

osmoregulators must expend energy to maintain osmotic gradients therefore they are actively transporting substances across cell memebranes

Question 19

land animals

Answer 19

have adaptations to reduce water loss
body coverings of most help to prevent dehydration
nocturnal lifestyle can help with water savings
maintain water balance by eating moist food and producing water metabolically

Question 20

nitrogenous waste

Answer 20

breakdown of proteins and nucleic acids
some animals convert toxic ammonia to less toxic compounds prior to excretion

Question 21

catabolism

Answer 21

breakdown of proteins and nucleic acids

Question 22

ammonia

Answer 22

animals that excrete nitrogenous waste as ammonia need access to lots of water
mostly fish who release it across whole body surface or through gills

Question 23

urea

Answer 23

mammals, most amphibians, sharks and some bony fishes
liver converts ammonia to less toxic urea

Question 24

How is urea excreted

Answer 24

circulatory system carries urea to kidneys where it is excreted
process of ammonia conversion to urea is energetically expensive
excretion of urea requires less water than ammonia

Question 25

uric acid

Answer 25

birds and many reptiles, insects, and lard snails
non toxic and does not dissolve in water

Question 26

how is uric acid excreted

Answer 26

as a paste with little water loss
more energetically expensive to produce than urea

Question 27

nephron

Answer 27

functional unit of the kidney

Question 28

functions of mammalian nephron

Answer 28

filtering blood requires 3 processes:
1. filtration
2. reabsorption
3. secretion

Question 29

functions of the kidney

Answer 29

filter the blood

Question 30

what is the flow of blood/filtrate?

Answer 30

• blood enters the kidney via renal artery which branches into arterioles
• osmolyte and water filtrate enters nephron
• nephron re-absorbs oosmolytes and water
• remaing filtrate drains from nephron into renal pelvis then ureter, then leaves body via urethra

Question 31

bowman’s capsule

Answer 31

tubular case surrounding glomerulus at beginning of nephron

Question 32

what enters nephron?

Answer 32

everything except blood cells and large proteins